#!/usr/bin/env node

//8. 管道方式连接多个外部程序

const cp = require('child_process');
const cat = cp.spawn('cat',['data.txt']);
const sort = cp.spawn('sort');
const uniq = cp.spawn('uniq');

cat.stdout.pipe(sort.stdin);
sort.stdout.pipe(uniq.stdin);
uniq..stdout.pipe(process.stdout); 

